Is Drylok A Vapor Barrier?

Would you like to know if Drylok is a vapor barrier? Well, we have looked into this topic and have answers for you. Knowing if Drylok is a vapor barrier is essential to know if it can be used as one.

Drylock is not a vapor barrier. Vapor barriers keep all water out, while Drylok creates a semi-permeable film that allows the material underneath to breathe.

In this article, we will take a closer look at Drylock and vapor barriers. We will also learn the answers to other interesting related questions, such as how to use Drylok for a basement, and some examples of good vapor barriers. Keep reading to learn more!

Is Drylok A Vapor Barrier?

Drylok is not a vapor barrier. Vapor barriers are designed to keep moisture out of a structure and don't allow any water through them.

Priming the wall

Drylok is designed to be semi-permeable to allow moisture out while preventing more water from entering. The problem is that if you use Drylok as the primary vapor barrier for a house, it will allow water to enter your walls gradually.

Water entering your walls can cause mold, which can be a health hazard. Water can also rot wooden beams and make the house structurally unsafe. Using a less permeable material as a vapor barrier would be best.

How Should I Use Drylok For A Basement?

How should i use drylok for a basement, Is Drylok A Vapor Barrier?

While you don't want to use Drylok as a vapor barrier, it does have some great uses for your basement. If water gets trapped in your walls, you will want to give it a place to go. If you use a vapor barrier on both the interior and exterior of your basement walls, water can get trapped and cause more damage.

One solution is to coat the interior of your basement walls with Drylok. If moisture gets in your walls, the Drylok will help it get out.

While Drylok can allow trapped moisture out of your walls while keeping them watertight, it can't help water damage. If water is already trapped in your basement walls, covering it in Drylok won't allow it to vent safely but will worsen the problem.

Drylok is only designed to vent moisture and not release trapped water. If you have water in your walls, you will need to fix the leak and replace the damaged drywall instead of covering it in Drylok.

What Is A Good Vapor Barrier?

Vapor barrier install on the walls

Many different materials make a good vapor barrier. Let's learn what materials make a sound vapor barrier and how they work.

Aluminum Foil

Aluminum foil makes an excellent vapor barrier, not allowing any water through. It is also corrosion resistant making it perfect for exposure to moisture over the years.

You can buy aluminum foil in large rolls to allow for easy application as a vapor barrier. If you want to try aluminum foil as a vapor barrier, here are two of the best products available on Amazon.

US Energy Products Aluminum Foil

You can find this product here on Amazon.

AES Aluminum Foil

You can find this product here on Amazon.

Poly-Coated Kraft Paper

Poly-coated kraft paper uses a polymer to create a strong vapor barrier. This material is so good a keeping water out that the National Institute for Science and Technology found it suitable as a vapor barrier for all climates in the US, including the south, which is known for its humidity.

Just like aluminum foil, you can buy poly-coated kraft paper in large rolls, which can be easily installed as a vapor barrier. If you want to try poly-coated kraft paper as a vapor barrier, here are two of the best available on Amazon.

Partners Brand Poly Coated Kraft Paper

You can find this product here on Amazon.

Aviditi Poly Coated Kraft Paper

You can find this product here on Amazon.

Elastomeric Paint

Elastomeric paint is paint that includes polymers to create a waterproof seal. These polymers dry to form a waterproof layer that can be used to create an effective vapor barrier.

Apply one to two coats of elastomeric paint, depending on the brand, to create a vapor barrier to protect your house. If you want to use elastomeric paint to create a vapor barrier, here are two of the best products available on Amazon.

AMES Blue Max Waterproofer

You can find this product here on Amazon.

Rust-Oleum Elastomeric Coating

You can find this product here on Amazon.

Foil-Faced Foam Board

Foil-faced foam boards use a layer of aluminum foil to create a waterproof vapor barrier. These panels can easily be attached to your basement walls to keep water out. They also work as excellent insulators to regulate your basement's temperature.

When using foil-faced foam boards, it's essential to use waterproof tape to seal the seams. If you use tape that isn't waterproof, like duct tape, the boards won't work as an effective vapor barrier.

Polyethylene Plastic Sheet

Polypropylene rolls for packaging

Polyethylene plastic sheets are large sheets of plastic that are highly effective as a vapor barrier. Another advantage of polyethylene plastic sheets is that they are economical. These vapor barriers cost less than many others.

If you want to try polyethylene plastic sheets as a vapor barrier, here are two of the best available on Amazon.

Frost King Polyethylene Sheeting

You can find this product here on Amazon.

X Pose Clear Poly Sheeting

You can find this product here on Amazon.

How Do You Install A Vapor Barrier?

Worker installing vapor barrier around the skylight opening

The exact method to install a vapor barrier will vary depending on which material you choose for your vapor barrier. Let's learn how to install a polyethylene plastic sheet vapor barrier since it's the most commonly used barrier, and then discuss what would be different when using other vapor barriers.

Measure The Room

The first step is to measure the area you are installing a vapor barrier. It would be best to use plastic sheets that reach from the ground to the roof and can wrap around the walls in one sheet. While it's okay if you can't use a single sheet, it would be best to limit seams as they can lower the integrity of your vapor barrier.

Once you know how many sheets of plastic you'll need to install, you can begin securing them to the wall.

Secure The Top

To secure the sheets to the wall, you will first want to secure the top. To do this, use a staple gun to attach the top corner of your vapor barrier to the wooden supports of the wall. Leave a six-inch lip of extra plastic at the top of the wall to let you caulk it later.

Next, keep stapling along the top of the wall ensuring the plastic is flush with the wall while you secure it. Once the whole barrier has been attached to the top of the wall, you can begin stapling the rest.

Staple The Barrier

Using a stapler to mounts a vapor barrier membrane

When stapling the plastic to the wall, you don't need to secure it to every wooden post. If you stapled in the middle and bottom of the plastic every two or three supports, it would provide plenty of connection.

Apply Acoustical Caulk

Once you are finished stapling the barrier to the wall, you must apply acoustical caulk along the top and bottom of the barrier. You will want to use acoustical caulk because when it dries, it won't shrink, which can leave cracks or gaps. If you use standard caulk, it will compromise the vapor barrier by not being fully waterproof.

Seal Seams

Finally, seal any seams between pieces of plastic sheets with vapor barrier tape. Vapor barrier tape is designed to be waterproof and will ensure your vapor barrier is entirely moisture-proof.

Other Materials

If you use any other material for a vapor barrier that comes in sheets, you can use the same process to secure them to your walls.

When using foil-faced foam boards, you will want to use construction adhesive to hold the board to your walls. Remember to seal the seams between the panels to ensure a sound vapor barrier.

If you're using elastomeric paint, you will want to coat the exterior wall in one to two coats to create a vapor barrier. In some situations, like the dirt floor of a crawl space, you can't use elastomeric paint and will want to use an alternative vapor barrier.

Final Thoughts

In this article, we learned Drylok is not a vapor barrier. We also learned about materials that make great vapor barriers and how to install them.

Remember, it's essential to ensure seams in your vapor barrier are correctly sealed, no matter the material.

We hope you enjoyed this article. If you want to learn more, check out some of these other posts.

Does A Vapor Barrier Cause Mold?

Vapor Barrier Paint Vs Plastic

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